The license key you have is valid for vSphere 6.x. Therefore, you can use this license on all versions of vSphere 6. So you can use version 6.0, 6.5, 6.7. You can upgrade from vSphere 6.5 to vSphere 6.7. The most important issue to note here is hardware compatibility. Can you send the brand model information of the physical server you used? Let's check for hardware compatibility.